Vendor dependencies

Let's see how I like this workflow.

vendor/wasm-bindgen/tests/wasm/jscast.rs

@@ -0,0 +1,88 @@
+use wasm_bindgen::prelude::*;
+use wasm_bindgen::JsCast;
+use wasm_bindgen_test::*;
+
+#[wasm_bindgen(module = "tests/wasm/jscast.js")]
+extern "C" {
+    type JsCast1;
+    #[wasm_bindgen(constructor)]
+    fn new() -> JsCast1;
+    #[wasm_bindgen(method)]
+    fn myval(this: &JsCast1) -> u32;
+
+    type JsCast2;
+    #[wasm_bindgen(constructor)]
+    fn new() -> JsCast2;
+
+    #[wasm_bindgen(extends = JsCast1)]
+    type JsCast3;
+    #[wasm_bindgen(constructor)]
+    fn new() -> JsCast3;
+
+    #[wasm_bindgen(extends = crate::jscast::JsCast1, extends = JsCast3)]
+    type JsCast4;
+    #[wasm_bindgen(constructor)]
+    fn new() -> JsCast4;
+}
+
+#[wasm_bindgen_test]
+fn instanceof_works() {
+    let a = JsCast1::new();
+    let b = JsCast2::new();
+    let c = JsCast3::new();
+
+    assert!(a.is_instance_of::<JsCast1>());
+    assert!(!a.is_instance_of::<JsCast2>());
+    assert!(!a.is_instance_of::<JsCast3>());
+
+    assert!(!b.is_instance_of::<JsCast1>());
+    assert!(b.is_instance_of::<JsCast2>());
+    assert!(!b.is_instance_of::<JsCast3>());
+
+    assert!(c.is_instance_of::<JsCast1>());
+    assert!(!c.is_instance_of::<JsCast2>());
+    assert!(c.is_instance_of::<JsCast3>());
+}
+
+#[wasm_bindgen_test]
+fn casting() {
+    let a = JsCast1::new();
+    let b = JsCast2::new();
+    let c = JsCast3::new();
+
+    assert!(a.dyn_ref::<JsCast1>().is_some());
+    assert!(a.dyn_ref::<JsCast2>().is_none());
+    assert!(a.dyn_ref::<JsCast3>().is_none());
+
+    assert!(b.dyn_ref::<JsCast1>().is_none());
+    assert!(b.dyn_ref::<JsCast2>().is_some());
+    assert!(b.dyn_ref::<JsCast3>().is_none());
+
+    assert!(c.dyn_ref::<JsCast1>().is_some());
+    assert!(c.dyn_ref::<JsCast2>().is_none());
+    assert!(c.dyn_ref::<JsCast3>().is_some());
+}
+
+#[wasm_bindgen_test]
+fn method_calling() {
+    let a = JsCast1::new();
+    let b = JsCast3::new();
+
+    assert_eq!(a.myval(), 1);
+    assert_eq!(b.dyn_ref::<JsCast1>().unwrap().myval(), 3);
+    assert_eq!(b.unchecked_ref::<JsCast1>().myval(), 3);
+    let c: &JsCast1 = b.as_ref();
+    assert_eq!(c.myval(), 3);
+}
+
+#[wasm_bindgen_test]
+fn multiple_layers_of_inheritance() {
+    let a = JsCast4::new();
+    assert!(a.is_instance_of::<JsCast4>());
+    assert!(a.is_instance_of::<JsCast3>());
+    assert!(a.is_instance_of::<JsCast1>());
+
+    let _: &JsCast3 = a.as_ref();
+    let b: &JsCast1 = a.as_ref();
+    assert_eq!(b.myval(), 4);
+}